The "Childmyths" blog is a spin-off of Jean Mercer's book "Thinking Critically About Child Development: Examining Myths & Misunderstandings"(Sage, 2015; third edition). The blog focuses on parsing mistaken beliefs that can influence people's decisions about childrearing-- for example, beliefs about day care, about punishment, about child psychotherapies, and about adoption.
See also http://thestudyofnonsense.blogspot.com

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Concerned About Unconventional Mental Health Interventions?

Wednesday, April 18, 2018

How Do We Know Whether an Intervention Is Effective? (E.g., PA Treatments)

There’s a lot of discussion right now about whether
psychological interventions are or are not evidence-based (or
empirically-supported) treatments. Even when there is strong evidence that a
treatment is efficacious—causes good
outcomes under ideal circumstances—there are further demands for evidence that
it is effective and causes good
outcomes in the less-than-ideal settings of the real world.

The strongest evidence in either case depends on
research that has used randomized
controlled trials. RCTs (not to be confused with residential treatment
centers!) are studies in which people who have received the treatment being
tested are compared to a control group
of people who have not received it (and may have had no treatment, or had a
well-established different treatment, or have been placed on a wait-list for
the treatment being tested). Because this kind of research is randomized, prospective patients do not
get to choose which group they want to be in, but are assigned to one or the
other in some objective way like the flip of a coin or the use of a list of
random numbers. The point here is to eliminate the bias that might be present
if people got to choose the treatment they want—just believing that something
will be good for them, or expecting that a treatment will be effective, can be
enough to change people’s moods and behavior. (If we’re talking about
treatments for children and adolescents, parents may be affected by their
expectations about a treatment so that they behave differently toward their children
if they think they are getting that treatment, or see their children’s behavior
differently if they think the children are getting a good treatment, or, of
course, both of these things.)

Having a control or comparison group as part of the
research design adds to what is called the internal validity of the study.
Internal validity is also influenced by factors like having a blinded
evaluation, or assessment of children by people who do not know them or know
what treatment they have been receiving or will receive. When parents, who know
both of these things to some extent (even if not told their children’s
treatment, they may figure it out from things the child tells them), are involved
in evaluation of the children’s response to treatment, other biases can creep
in; parents are the ones to say whether they liked a treatment, but can not say
objectively whether it helped their children. A number of alternative
therapies, like Love & Logic training for parents, make the mistake of
asking parents whether their children have improved and then acting as if it is
known what changes have really occurred in the children.

Many studies that claim to give evidence supporting
unconventional, alternative therapies are more than one step below RCTs. They
look very simply at measures (often parent opinions) taken before and after
treatment. Does this seem like a good idea? Well, only if you think that
children and adolescents do not change unless they are made to change by an
intervention!

I recently had pointed out to me the statement by a
guardian ad litem that changes she
heard about in a girl between ages 11 and 13 could only have been caused by a
PA treatment method the girl had experienced. It would appear that the GAL
thought that nothing happened in those two years other than the treatment and
separation from the preferred parent. But in fact much had happened.

A small amount of the change reported was no doubt due
to adjustment over a couple of post-divorce years, during which one parent had
remarried. A much larger factor, causing changes of all kinds, physical and
mental, was the occurrence of puberty for
this girl—just under 13years being the average age of menarche (first
menstruation) in the Western world today. Puberty in both sexes is associated
with dramatic social and cognitive changes and the redirection of “attachment”
and positive social attitudes toward peers and away from parents. Height and
weight increase, breasts develop, hair and skin change, all producing a mixture
of delighted and anxious feelings about the self, and further reducing (though
not eliminating) the adolescent’s concern about relationships with parents.

Maturation, the
series of developmental changes that is largely governed by genetic programs,
is rapid and intense during this period when “nothing happened” except the PA
intervention. Without good research design that takes maturation into account,
studies of PA or other interventions for children and adolescents are wrong if
they claim they show the influence of their intervention. Because children and
adolescents are always changing—most rapidly around puberty, beginning about
age 9 in girls—every study of a psychological treatment for them needs to have
a control group, similar to the treated group but nor receiving the treatment,
whose characteristics will show us the natural maturational changes that occur
during an age period. The effect of the PA or other intervention is shown
(roughly speaking) by subtracting:

There would be many other technical details to be
considered in designing a good study of PA or other interventions, but the two
mentioned here, blind evaluation and a control for maturational change, are
absolutely critical.

About Me https://en.wikipedia.org/wiki/Jean_Mercer

Jean Mercer has a Ph.D in Psychology from Brandeis University, earned when that institution was 20 years old (you do the math). She is Professor Emerita of Psychology at Richard Stockton College, where for many years she taught developmental psychology, research methods, perception, and history of psychology. Since about 2000 her focus has been on potentially dangerous child psychotherapies, and she has published several related books and a number of articles in professional journals.
Her CV can be seen at http://childmyths.blogspot.com/2009/12/curriculum-vitae-jean.mercer-richard.html.